My ex and I had a joint brokerage account, which earned capital gains. We can't file jointly because we're divorced. It's joint income. How do we file this?

My ex-wife and I had a joint brokerage account, which earned us a total of about $3000 in capital gains. We can't file jointly now because we're divorced. The income is for a joint account, so it's both of out income. Does one of us choose to claim it? Do we each claim half of it? Do we have a choice?